Adjustable cam



June 17, 1930. H. F. ELLIOT-r 1,763,957

ADJUSTABLE GAM Original Filed?, Nov. 27. 1926 lill/1111111 n l' auchan,v

Patented June 17, 41930 HAROLD F. ELLIOTT, OF PALO ALTO', CALIFORNIA, ASSIGNOR, BY`DIRECT AND MESNE ASSIGNMENTS, TO VICTOR TALKING MACE-HNE COMPANY, F CAMDEN, NEW JERSEY,`

.A CORPORATION 0F NEW JERSEY ADJUSTABLE CAM Original application filed November 27, 1926, Serial No. 151,134. Divided and this .application lc.

February 1, 1928. Serial No. 251,165.

This invention relates to a cam structure, and particularly to one that can have its active surface smoothly adjusted.

rl`his application is a division of my rior application Serial Number 151,134, iiled November 27, 1926, and entitled Tuning system.

It is one of the objects of my invention to make it possible to adjust a cam surface so that it will conform with any desired predetermined curve Within the limits of adjustment.

In adjustable cams, it is known to provide avseries of adjustable screws to which iso- 1, lated parts of the cam are fastened, so that by moving the screws, the positions of these parts can be adjusted. However, it is obvious that such a cam forms a discontinuous surface. It is another object of my invention to make it possible to adjust such a cam surface and yet ensure that it will remain smooth and continuous.

My invention possesses many other advantages, and has other objects which may be made more easily apparent from a consideration of one embodiment of my invention. For this purpose I have shown a form in the drawings accompanying and forming part of the present specification. I shall now proceed to describe this form in detail, which illustrates the general principles of my invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of my invention is best defined by the appended claims.

Referring to the drawings:

Figure 1 is a top plan View, partly in section, of a cam and its associated parts constructed in accordance with my invention;

Fig. 2 is an enlarged sectional view, taken along plane 2-2 of Fig. 1; and

Fig. 3 is an enlarged detail section, taken along plane 3-3 of Fig. 1.

To form the active cam surface, I utilize one or more yielding strips 108 that can be readily made .to conform with the desired contour. A support for the vstrip can be arranged across which itis stretched, the support, being formed by a series of adjustable members closely spaced, such as the screws 111. These screws can loe carried by a supporting member 87 shown in. the pres cnt instance as circular in outline. This member has a flange 88 and a peripheral groove 109 in the iiange, which is wide enough to permit entry of strip108.

The adjusting screws 111 are shown as projecting through flange 88 at an angle so as to facilitate adjustment by the aid of a screwdriver. A coiled spring 110 or equivalent means can be used to stretch the cam strip 108 across the closely spaced screw'tips, and is anchored as shown in Fig. 1, to the ends of the strip. In this way, tension is applied to the strip, and it conforms closely to the adjustable screw tips.

The wheel 87 is arranged to'be rotated so that the cam surface vmay actuate one or more cam followers, such as the rollers 106 held against the strip 108, For this purpose, the wheel 87 can be provided with a shaft 113 journaled in a support 59. Move- .ient can be imparted to vcam wheel 87 as by a pair of links 114, 115 diametrically opposite each other and having clevises 91 which are pivotally mounted on pins 92 fastened t-o the Hangs 88. These clevises are accommodated, as shown in Fig. 3, between the upper and lower washers 941 and 93 that are supported on the pins 92.

It is evident that each of the screws 111 can Vbe individually adjusted to vary the height of the cam at that point. The yield ing connection 110 permits the strip 108 to slide over the screws so as to form anl uninterrupted, continuous surface.

The cam structure is arranged to actuate any form of mechanism. In the present instance'it is shown as actuating a series of variable electrical condensers by Iacting on the followers 106. These followers are rotatably mounted on the free ends of levers 105. These levers are each fixed on the ends of the shafts journaled in bushings 103 in bosses 104. These bosses are shown as integral with support 59. Fixed to the shaft are a series of spaced condenser plates 62; and when this shaft is' rotated by the cam structure, these plates interleave to a greater or less extent with another set of plates 61 to form a variable electrical capacity. The particular details of this capacity variation are disclosed and claimed in my parent application, and therefore fui'- ther elucidation thereof is unnecessary, except to state that a 'spring'107 is used to hold the follower 106 against the c'a-m and outward in said supporting element, a'

flexible cam strip carried by said element surrounding and in contact with said adjustable abutments, said strip being free to move longitudinally with respect to said abutments, a cam follower bearing on said flexible strip, and resilient means acting endwise of said strip for stretching vthe latter over the ends of said abutments.

3. A cam structure comprising a supporting element, a plurality of adjustable abutments on said element and extending radially outward from the periphery thereof, said abutments being adjustable radially inward and outward in said supporting element, a

, flexible cam strip carried by said element Cil surrounding and yin contact with said adjustable abutments, said strip being free to move longitudinallyfwith respect to said abutments, a cam follower bearing on said flexible stripfand a spring joining the ends of said strip forvstretching the latter over the ends of saidabutment's.

4. A cam structure ycomprising a rotatable member having a peripheral groove, a plurality of adjustable abutments on said member and extending radially outward at the periphery thereof, said abutment-s :being adjustable radially inward and outward in said supporting member, andthe ends of said abutments being positioned in said groove, a flexible cam strip carried by said member, said cam strip being positioned in said groove in Contact with the ends of said abutments and being free to move longitudinally with respect thereto, a cam follower riding in said groove onsaid flexible strip, and resilient means attached to the end or ends of said strip for stretching the same over the ends of said abutments.

In testimony whereof I have hereunto set my hand;

HAROLD F. ELLioTT.

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